<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, user-scalable=no, initial-scale=1.0, maximum-scale=1.0, minimum-scale=1.0">
<title></title>
</head>
<style>
body{
	margin:0px;
}
svg{
				position: absolute;
				left: calc((100% - 375px)/2);
}
</style>
<body>
<svg width="375" height="667">
				<defs>
					<radialGradient id="Gradient" cx="0.5" cy="0.5" r="0.5" fx="0.25" fy="0.25" spreadMethod="reflect">  
						<stop offset="0%" stop-color="red"></stop>
						<stop offset="100%" stop-color="blue"></stop>
					</radialGradient>		
				</defs>
<rect x="10" y="10" rx="15" ry="15" width="100" height="100" stroke="black" fill="url(#Gradient)"></rect>
</svg>
</body>
</html>
